Method of making brake drums



July 28, 1936. D. J. CAMPBELL METHOD OF MAKING BRAKE DRUMS Original Filed-June 15, 1951 UNITED STATES PATENTi'OFFlCE METHOD MAKING BRAKE DRUMS Donald J. Campbell, Spring Lake Township,

' Ottawa County, Mieln, sssignor to Campbell,

Wyant a Cannon Foundry Company, Muskeg on Heights. Mich.,a corporation of Michigan Original No. 2,035,142, dated March 24, 19st,

Serial No. 544,350, June 15, 1911, Applieal tion for reissue May 16, 1936, Serial No. 80,050

4 Claims. (oi-apnea) This invention relates to a method of manufacturing composite-drums, the invention beins particularly useful in connection with brake drums which are usedwith automobiles, though useful inother relations.

I have heretofore filed an application for a patent. Serial No. 512,792, on February 2', 1931, wherein an intimate and in' effect an integral ioinder of a cast iron band of the inner side of an outer cylindrical band or drum of metal which may be pressed, rolled or otherwise preformed into shape is disclosed, and the process essentially conlists in the projection of molten cast iron at a v'ery high degree of temperature, approximating I 2800' I".. against theinner curved side of the preiormed'band or drum which is rotated and likewise is heated to a high temperature but less than the molten cast iron, the temperature of the drum being approximately 1400 I". This resultsin'a 'mbstantial fusing of the inner surface-portion oi the'outer drum member with the cast iron.

The apparatus which is disclosed in said pending application for'patent, and the process which is followed out thereby is a very practical one,

but; I have improved the same, particularly in the matter of rapidity of production with resultant economy and with the elimination of certain parts of the mechanism and apparatus thereln'shown which previously has resulted in slowing and curu tailingthequantity andraisingexpenseofprowith thepresent invention 11-. is designed um theouterdrumbandsofformedmetalshallbeof double width,andthatthe castironshallbe pro ieetedthereagainstthedrumhested toahlgh degree of temperature and revolving as described in my pending application. and at each outer edge of the drum outermember itis provided with an inturned annular lip which serves as a g dam'for themoltenmetal, keeping itiromrun- 'ning outwardly and obviating the necessityof application and as is when the molten 4| meteliseppliedtoasinglebrakedrumelement.

The present invention pennits the application of the cast iron wearing band at the inner side preformed outer drum'memberof double more quickly and more rapidly than the width of drum illustrated and described in the pending application referred to, there is an enhancement-of quantity production,

mum m m mm' m between the mm mm m nection with the accompanying drawing, in which,

complete composite brake drum bands, the divid ing or cutting operation being one which is simply and easily performed.

01 secondary importance to the speeding up of production is the obtaining of a set of absolutely 5 matched drums. The inner surface of the drum before the cast metal has been applied thereto is of identical diameter entirely along its length as a y it is integrally and simultaneously formed and .hence the above construction necessarily follows; In

similarly, after the cast metal has been added, the samecondition obtains; and; finally, after the finishing cut, it such cut is desired, the double unit; as yet undivided, is equal as regards all of its several diameters. Thus, a perfectly balanced 15 pair of brake dmms is produced by my unique process or method.

An understanding of the invention may be had from the following description, taken in con- I'ig. 1 is a side elevati and section illustratlog the manner in which he molten cast metal is projected and deposited" against the revolved double width drum band.

v Fig. 2 is a vertical section through the composite double width drum band after the cast metal has been applied thereto. Fig. 3 is an enlarged transverse section through one side of the composite drum band. v

. .l 'ig. 4 illustrates the structure in Fig. 3 after a circumferential division thereof in two Fig. 5 is a fragmentary section showing the manner in which each of the drum parts shown in Fig. 4 may be welded to a brake drum back or web.

Fig. 6 is a fragmentary section showing th manner in, which each of the drum parts shown in Fig. 4 may have a brake drum back'or web welded to the continuous annular flange.

Like referencecharacters refer to like parts in 40 the different figures of the drawing.

The first step in the process of manufacturing the composite drum is to form a continuous annular outer member of flat metal of quality such that it can be readily rolled or pressed.

This outer member I at'spaced apart points is formedwith outwardly projecting annular ribs 2,

.sections 3 extending outwardly from the ribs in the same plane with the middle portion i be tween said ribs, and each of the sections 3 at its outer edge is-turned'inwardly for a short distance, providing a continuous annular flange I which than a This is disposed at an angle slightly greater right angle to the adiecentsections I. outer member. is subjected to heat to raise its temperature and rotated rapidly about itsaxisthesameasdescribedinmypendingapplication referred to. Molten cast metal is pro- Jecied against the inner face 01' the outer member thereby providing a continuous inner lining band I with integral ribs I e xtendingjtherei'rom into the pressed or rolled ribs! inKthe outer member. The molten metal is shown at I as projected by gravity downwardly and in a direction slightly opposite to the rotation of the drum. the rotation of which is indicated by the arrows, the metal coming froma med ladle or other receptacle, indicated at I, all of which is fully described and set forth in my prior pending III-9 plication tor pa'tent.

One feature of the invention resides in the sired quantity oi molten metal in place and outward lateral flow of the excess of molten metal 1 will be caused.

After the double width composite band structure has been produced in the manner described vit is split or divided midway between its opposed.

edges, as at I in Fig. 4, cutting the composite structure shown in Fig. 3 into two identical drum flange members each of which has apart is which is substantially onc haIf of the other part I between the ribs 2, and a, lining in which is one-half of the double width lining I shown in Fig. 3. The brake'drum may be completed by weldingaweborback lltothecutedgessasclearly shown in Pig. 5. The web or back II has a flange II extending back of the part to whereby a good joint is obtained between the several Or,ifdesired,aweb orbak llmaybewelded totheoutersideoftheannularriblasshown inl"ig.6.

Asstated abovethe merit resulting in simplification oi the process,

elimination of troublesome complications in apaxis, depositing molten metal in the invention is one of great amass I paratus and mechanism used for carryingout the process and further resulting in large quantity. production at a minimum 01 cost. 7

The invention is deflned in the appended claims and is to be considered comprehensiveof I all forms of structure coming within their scope.

I claim: g l. The process of manufacturing two brake drums which consists in providing a cylindrical shell'having an inwardly extending flange at, 10 I each end thereof, inserting a lining band in- .teriorly of the shell, cutting the shell and band midway between their ends and attaching webs to each of said flanges. 2. The process of manufacturing two brake ll .drums which consists in providing a rotating cylindrical shell having an inwardly extending flange of predetermined height at each end thereof, feeding a quantity of molten metal interio'rly of said shell while the same is rotating, ll whereby the molten metal levels as between the flanges, permitting the metal to cool, cutting the shell and its lining intermediate its ends, and finishing the inner peripheral face of the metal of each drum provided by said cutting. ll

3.The process of towing a pair of brake drums, which consists in providing a heated cylindrical body having an inturned flange at each oi its ends, said, ends being unobstructed. inserting fluid metal 0! difleren't composition" through one of said unobstructed ends against the inner surface or said body, rotating the body and permitting the metal to cool while subjected to centrifugal action and then se 7 the body and metal substantially midway of its length. 4. The process of manufacturing brake drums which consists, in providing a cylindrical shell having an inwardly extending annular flange at each end thereof, rotating said shell about its so trough provided by said shell and flanges, said flanges retaining the molten metal against escape to thereby provide a c'entriiugally cast metal lining'to said shell, and attaching a'brake drum web to a flange- DONALD J. CAMPBELL. 

